When a partnership, S corporation, trust, or estate files for a K-1 deadline extension, the Schedule K-1 you are waiting on will not arrive by the usual March 15 or April 15 date. Instead, expect it by September 15 for partnerships and S corporations, or September 30 for trusts and estates. That timing almost always pushes recipients to extend their own Form 1040 as well, because the K-1’s income and deduction figures are needed to file an accurate individual return.
The Extended K-1 Dates by Entity Type
The K-1 deadline is tied to the entity’s own tax return deadline. When the entity files Form 7004 before its original due date, both the return and the K-1s to owners or beneficiaries shift together.1Internal Revenue Service. Instructions for Form 7004
- Calendar-year partnerships (Form 1065) and S corporations (Form 1120-S) get a six-month extension, moving the deadline from March 15 to September 15.
- Calendar-year trusts and estates (Form 1041) get a five-and-a-half-month extension, moving the deadline from April 15 to September 30.2Internal Revenue Service. Forms 1041 and 1041-A – When to File
If the extended date falls on a weekend or federal holiday, it shifts to the next business day. So a partner in a calendar-year partnership that extends may not see a K-1 until mid-September, and a trust beneficiary may wait until the end of that month.
How the Entity Gets the Extension
The entity files IRS Form 7004 before its original filing deadline.3Internal Revenue Service. About Form 7004 No approval is required. As long as the form is submitted on time and any estimated entity-level tax is paid, the extension is automatic. Form 7004 extends time to file, not time to pay: any tax owed by the entity is still due on the original date.
You will not usually control this decision as a K-1 recipient. What matters for you is confirming with the entity whether it extended, and if so, when to expect the K-1.
What to Do About Your Own Return
Your Form 1040 is still due April 15 even if you know the K-1 will not arrive until September. You have two things to handle by that date: extending your filing deadline, and paying what you owe.
To extend, file Form 4868 by April 15. That grants an automatic six-month extension and moves your filing deadline to October 15. You do not have to file the form separately if you make an electronic tax payment by April 15 and mark it as an extension payment; the IRS processes the extension when the payment posts.4Internal Revenue Service. Form 4868 – Application for Automatic Extension of Time To File U.S. Individual Income Tax Return
Then pay. Your individual extension only buys time to file, not time to pay. Estimate your liability using the prior year’s K-1 and any current-year information the entity has shared (draft financials, interim distributions, communications from the general partner or trustee). Send that estimate to the IRS by April 15. If the final K-1 later shows materially different numbers, file an amended return on Form 1040-X once you have the accurate figures.5Internal Revenue Service. File an Amended Return
Avoiding Underpayment Penalties While You Estimate
Estimating tax without a final K-1 is where underpayment penalties tend to hit. The IRS assesses those penalties under IRC 6654 when you have not paid enough by the deadline, but two safe harbors shield you if you meet either one:6Office of the Law Revision Counsel. 26 USC 6654 – Failure by Individual to Pay Estimated Income Tax
- Pay at least 90% of the tax you actually owe for the current year, or
- Pay at least 100% of the tax shown on your prior-year return. If your prior-year adjusted gross income was over $150,000 ($75,000 if married filing separately), the threshold rises to 110%.
The prior-year method is the safer play when a K-1 is outstanding. You already know last year’s total tax, so you can hit that number with certainty regardless of what the new K-1 turns out to say. Check your prior-year AGI first; the 110% rule catches people with volatile partnership income who assume the flat 100% applies to them.
If the K-1 Never Arrives
Sometimes the K-1 does not show up even after the extended deadline. Start by contacting the entity, but if that goes nowhere, file Form 8082 with your tax return. That form notifies the IRS that you did not receive a Schedule K-1 by your filing deadline, including extensions.7Internal Revenue Service. Instructions for Form 8082
Filing Form 8082 puts the IRS on notice and protects you if the entity later reports figures that differ from yours. You still report your best estimate of income from that entity, using whatever you have: the prior-year K-1, interim financials, or written communications from management. If the K-1 eventually arrives and the numbers change, amend on Form 1040-X.